Transvenous catheters are known for use in invasive cardiac pacing. Such catheters have a distal end which can be inserted, via a vein of a patient, into the appropriate chamber of a patient's heart so as to carry out a pacing operation.
It's also been known to use transvenous catheters, at least experimentally, in esophageal pacing. Such catheters have first and second spaced-apart electrodes located on a distal end thereof. The electrodes are positioned in the esophagus appropriately with respect to the posterior surface of the patient's heart so as to carry out a pacing operation. Results of experiments using such bipolar transvenous catheters for esophageal pacing were presented, in part, at the Fifty-Third Scientific Sessions of the American Heart Association, Nov. 19, 1980. Results of that work were subsequently published in the journal Circulation in 1982.
Notwithstanding the above-noted uses for transvenous catheters, none of the known transvenous catheters provide any adjustment of the flexibility or stiffness thereof during insertion. Further, transvenous catheters at times terminate in a hard electrode member which can cause some discomfort to the patient on insertion through the nasal passages into the esophagus.
Hence, there continues to be a need for costeffective esophageal pacing catheters which are readily inserted and which cause minimal patient discomfort and/or trauma.